1. Field of the Invention
The present invention relates to fuel shut-off valves for engines, and, more particularly, to an automatic fuel pump outlet shut-off valve for diesel engines.
2. Description of the Related Art
Engines are typically connected to a fuel storage tank via a fluid system including a fuel pump for conveying fuel from the tank to the engine. In a fluid system such as that typically located in a vehicle, a filter is disposed in the fuel line extending between the fuel tank and the engine at a location upstream from the engine. The filter functions to remove contaminants from the fuel which can cause damage to the internal components of the engine. Over time, a fuel filter can become obstructed and cause substandard vehicle operation, thereby making servicing of the fuel filter a priority. When this occurs, the vehicle operator may be tempted to remove the fuel filter to increase vehicle performance. If the fuel filter is removed, contaminants located within the fuel are not removed and are allowed to circulate through the vehicle""s engine. The free flow of contaminants through the engine can cause problems including collection of particles within the valves of the engine, clogging of fuel injector jets, or scoring of the internal surfaces of the engine. Furthermore, if the vehicle has been operated with the fuel filter removed, service providers may be reluctant to honor warranties for damaged parts.
Alternatively, the vehicle operator may choose to service or replace the fuel filter. To perform service or replacement of the filter, the filter lid must be removed. When the filter lid is removed, a potential hazard exists for spraying fuel on to a service person and engine if the ignition is inadvertently turned to the xe2x80x9conxe2x80x9d position, thereby energizing the fuel pump.
The present invention provides an automatic pump outlet shut-off valve. The shut-off valve is illustrated for use in a diesel engine, but may also be used in other engine types. The shut-off valve prevents operation of the engine if a fuel filter is not present. Additionally, the disclosed valve permits engine operation only after the filter lid is tightened and properly positions the filter within the filter cavity. The disclosed valve also prevents the discharge of fuel from the fuel pump when the filter lid is removed to replace or service the fuel filter.
The present invention, in one form thereof, comprises a fuel filtering system for use in a fuel line extending between a fuel source and an engine which includes a fuel pump operably disposed in the fuel line between the fuel source and the engine and a valve member operably disposed in the fuel line between said fuel pump and the engine. The valve member has an open position and a closed position wherein the valve member permits passage of fuel through the fuel line when in the open position and prevents the passage of fuel through the fuel line when in the closed position. A biasing member engaged with the valve member biases the valve member towards the closed position. A fuel filter is mountable in the fuel filtering system and has a filter structure and a filter element extending from the filter structure. The filter element defines an interior volume and the fuel pump is at least partially disposed within the interior volume of the filter element. An actuating surface is located on the valve member and is engageable to bias the valve member towards its open position. Mounting the fuel filter to the fuel line engages the fuel filter with the actuating surface and thereby moves the valve member into the open position.
The fuel filtering system described above, may also include a housing defining a filter cavity with the fuel filter being positionable within the filter cavity. A removably attachable lid provides access to the filter cavity and also secures the fuel filter within the cavity. At least a portion of the fuel pump and the valve member are disposed within the housing and are positioned so that the valve member prevents the entry of fuel into the filter cavity when the valve member is in the closed position. The lid may also be configured whereby attachment of the lid to the housing biases a fuel filter located within the filter cavity into engagement with the actuating surface and thereby moves the valve member into the open position and wherein the lid is spaced from the actuating surface when the lid is attached to the housing and the valve is in the closed position whereby the valve member remains in the closed position when the lid is attached to the housing in the absence of the fuel filter.
The present invention, in another form thereof, comprises a fuel filtering system for use in a fuel line extending between a fuel source and an engine. The system includes a filter housing defining a filter cavity wherein the filter cavity defines a portion of the fuel line. A fuel pump is operably disposed in the fuel line between the fuel source and the engine and is at least partially disposed within the housing. A valve mechanism having a body defining a valve opening and a valve member operably disposed within said valve opening defines a second portion of the fuel line and is disposed in the fuel line between the fuel pump and the filter cavity. The valve member has an open position and a closed position wherein the valve member permits passage of fuel through the fuel line when in the open position and prevents passage of fuel through the fuel line when in the closed position. A biasing member is engaged with the valve member and biases the valve member towards the closed position. A fuel filter is mountable within the filter cavity and has a filter structure and a filter element extending from the filter structure. The filter element defines an interior volume and the fuel pump is at least partially disposed within said interior volume. An actuating surface is located on the valve member and is engageable to bias the valve member towards the open position. Mounting the fuel filter within the filter cavity engages the filter structure with the actuating surface and moves the valve member into the open position.
The above described fuel filtering system may have a filter structure which sealingly engages the valve body proximate the valve opening and defines at least one passage proximate the valve opening. Fuel flowing through the valve opening towards the engine is thereby inhibited from directly entering the interior volume of the fuel filter by the sealing engagement of the filter structure with the valve body and is communicated to the filter cavity through the at least one passage.
The fuel filtering system may also include a lid removably attachable to the housing, removal of the lid providing access to the filter cavity and attachment of the lid securing the fuel filter within the filter cavity. The lid may also be configured whereby attachment of the lid to the housing biases a fuel filter located within the filter cavity into engagement with the actuating surface and thereby moves the valve member into the open position and wherein the lid is spaced from the actuating surface when the lid is attached to the housing and the valve is in the closed position whereby the valve member remains in the closed position when the lid is attached to the housing in the absence of the fuel filter.
The valve body of such fuel filtering systems may be disposed on the fuel pump with the valve opening defining the fuel pump outlet.
The valve member of such fuel filtering systems may also include a first major surface wherein when the valve member is in the closed position the first major surface is positioned so that impingement of fuel in the fuel line on the valve member biases the valve member towards the closed position
An advantage of the present invention is that it provides a simple, low cost, and effective fuel shut-off valve for a fuel filter and fuel pump combination.
Another advantage of the present invention is that it provides a fuel shut-off valve which prevents the engine from starting if a fuel filter is not installed.
Yet another advantage of the present invention is that it provides a shut-off valve which, when the filter lid is removed, automatically prevents the discharge of fuel from the fuel pump to prevent the spraying of fuel into the surrounding environment.